In the field of data processing, different tasks may require respective electronic systems widely divergent as to processing speed, storage capacity and reliability. Commercially available data processors are generally rigidly structured and are frequently adapted to a specific purpose only through the utilization of a duly designed logic network. It is of course possible to use a processor whose speed and capacity are larger than those required, yet such a more complex system involves a higher failure probability; furthermore, its cost is higher than that of a commercially available processor whose speed, capacity and reliability matches the existing requirements.
In the area of telecommunications, sequences of repetitive operations with low decision levels are performed on enormous amounts of data, e.g. on subscriber-line signal-level transitions accompanying the selection of call-number digits. Such repetitive operations are generally performed by a specialized computing device, called a "preprocessor", which is connected via an interface to a main processor. Disadvantages inherent in the utilization of two basically different devices include a higher probability of failure aggravated by the necessarily specialized communication interfaces, higher maintenance and operating costs, and increasingly difficult technical control due to the necessity of providing two different checking systems, one for the preprocessor and one for the main processor.